milter-reject: END-OF-MESSAGE from smtp143.junkemailfilter.com[69.50.231.143]: 4.7.1 Service unavailable - try again later; from=<address@hidden>

[J4K]

Morning all,

    Each day for the past 2 months, there are these rejects from
spamass-milter.  I don't really understand what these are caused by. 
Junkemailfilter is used as the secondary MX, but it should deliver. 
Every message is the same as below. Same Sender and same Rcpt:
   
Mar  4 01:57:43 logout postfix/cleanup[28334]: EC995846C9:
milter-reject: END-OF-MESSAGE from
smtp143.junkemailfilter.com[69.50.231.143]: 4.7.1 Service unavailable -
try again later; from=<address@hidden>
to=<address@hidden> proto=ESMTP helo=<junkemailfilter.com>
Mar  4 06:53:32 logout postfix/cleanup[31287]: 0B93480A71:
milter-reject: END-OF-MESSAGE from
smtp143.junkemailfilter.com[69.50.231.143]: 4.7.1 Service unavailable -
try again later; from=<address@hidden>
to=<address@hidden> proto=ESMTP helo=<junkemailfilter.com>
Mar  4 08:18:56 logout postfix/cleanup[31697]: A66B9817C4:
milter-reject: END-OF-MESSAGE from
smtp143.junkemailfilter.com[69.50.231.143]: 4.7.1 Service unavailable -
try again later; from=<address@hidden>
to=<address@hidden> proto=ESMTP helo=<junkemailfilter.com>

Does this make any sence here.  I am concerned that legitimate bounced
messages are being rejected by the SA milter.

Best wishes, S.